About "Light", need better understanding of it.

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Discussion Overview

The discussion centers around the nature of light, including its types, properties, and sources. Participants explore differences between various light sources such as lasers, flashlights, and sunlight, as well as concepts of illumination and darkness.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants inquire about the differences between types of light and light sources, questioning why flashlights and the sun behave differently in terms of illumination.
  • One participant explains that light consists of photons with specific wavelengths, noting that both stars and flashlights generate photons but in vastly different quantities.
  • Another participant emphasizes that visible light is just a small part of the electromagnetic spectrum and discusses the nature of electromagnetic waves and photons.
  • It is noted that the energy output of a light source, such as a flashlight versus the sun, determines its brightness and illumination area, with the sun having a significantly larger energy reserve.
  • Participants clarify that the characteristics of light sources, such as power and spectrum, vary due to different underlying physical processes.

Areas of Agreement / Disagreement

Participants express differing views on the nature of light and its sources, with no consensus reached on the broader implications of these differences. The discussion remains unresolved regarding the deeper understanding of light and its properties.

Contextual Notes

Some limitations in the discussion include the lack of detailed definitions for terms like "illumination" and "darkness," as well as assumptions about the audience's prior knowledge of electromagnetic theory.

lukestar
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Is there different types of light/particles of light? because all of these lights are different how it works, laser light, light from flash light, sun light. Why does flash light only illuminate only less area/more area depending on how much volts the battery is and a sun illuminates a whole Earth and stays on illuminating? What is darkness in a room with light off and what is illumination in a room with light on?
 
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Are you really asking why a flashlight isn't like a star?

Light are photons of a certain wave length. Both a star like our sun and a flashlight generate them, only one of them generates a lot more of them.
So light has two properties. The number of photons and their energy/wave length/frequency.

What is darkness? No photons hitting your retina and thus no nerve signal to your brain.
 
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If you're in a room where nothing moves then you will hear no sound, nothing will hit your ear drum. The harder you hit something, meaning the more energy you put into it the more that will reach your ear.
 
lukestar said:
Is there different types of light/particles of light?

Visible light is but one small section of the larger electromagnetic spectrum. Light, and everything else on this spectrum, is first and foremost an electromagnetic wave. This EM wave interacts with matter via 'photons', which we call the particle of light. (But in reality they are nothing like a particle in the classical sense) The only difference between, say, radio waves and visible light, is that radio waves have a much longer wavelength and much smaller energy per photon than visible light.

lukestar said:
Why does flash light only illuminate only less area/more area depending on how much volts the battery is and a sun illuminates a whole Earth and stays on illuminating?

Creating light requires energy. A flashlight only puts out a small amount of energy per second in the form of light, while the Sun puts out an enormous amount thanks to its temperature and sheer size. (Energy per second is known as 'power') The more power your flashlight puts out, the brighter the light is. A flashlight's energy source is its battery, which only holds a small amount compared to the Sun. The Sun simply has a much, MUCH larger reserve of energy in the form of gravitational potential energy and nuclear fusion. So while your flashlight can only stay lit up for a few hours, maybe a day or two if you have a newer LED flashlight, the Sun can shine for billions of years.
 
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lukestar said:
because all of these lights are different how it works, laser light, light from flash light, sun light.
What you are writing there are light sources, not the light itself. Some basic properties of light have been pointed out by Drakkith. While those lightsources emits different light characteristics (e.g. power, spectrum, directionality, coherence) because the underlying physics behind the generation is different as well.
 
Thank you all for the answers! :)
 

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